1. Field of the Invention
The present invention relates to a connector which is arranged to prevent detachment of a terminal from a terminal storage chamber by having a locking arm which engages the terminal inserted within the terminal storage chamber.
2. Related Art
A conventional connector having a locking arm (lance) for preventing a terminal from being come out is disclosed in JP-A-9-283203, JU-A-5-31138, JU-A-5-41068, or the like.
FIGS. 16 to 18 show the arrangement of such a conventional connector, wherein terminal storage chambers 2 for receiving terminals 3 therein are formed and aligned in a housing 1. Each of the terminal storage chambers 2 is provided with a locking arm 4 which engages with the terminal 3 inserted within the chamber. As shown in FIG. 17, the locking arm 4 is arranged to engage with the rear side of the contact portion 5 of the terminal 3 thereby preventing the terminal 3 from coming out from rear side of the housing 1.
In such a connector, in order to bend the locking arm 4 to the direction opposite to the engaging direction with the terminal 3, that is, to the outside direction of the housing 1, an opening portion 6 in an opened state is formed at the portion forming the locking arm 4 in the housing 1. In other words, the opening portion is formed so that the locking arm 4 can be bent outside to release the engagement of the locking arm 4 with the terminal 3 thereby making it possible to extract the terminal 3 from the housing 1. This opening portion 6 is normally covered by a cover (not shown) attached to the housing 1.
If the locking arm 4 is bent to a greater extent than needed, the locking arm 4 may be deformed or broken. In order to prevent such a phenomenon, an excessive deformation prevention plate 7 for preventing the excessive deformation of the locking arm 4 is provided. The excessive deformation prevention plate 7 is provided which is slidable within the housing 1 and arranged in a manner that the tip portion thereof serving as a free end covers the locking arm 4 thereby preventing the excessive deformation of the locking arm 4. An operation portion 8 extracted outside of the housing 1 is provided at the excessive deformation prevention plate 7 so as to continue therefrom. The excessive deformation prevention plate 7 can be moved backward by rotating the operation portion 8, whereby the bending operation of the locking arm 4 becomes possible.
However, in the conventional connector, if an excessive stress is applied to the locking arm 4 in the case of bending the locking arm in order to extract the terminal 3, both the locking arm 4 and the excessive deformation prevention plate 7 may be bent excessively outside as shown in FIG. 18. This is because the tip portion of the excessive deformation prevention plate 7 is arranged to be a free end. If the locking arm is bent excessively, since the locking arm 4 may be deformed or broken (see the lower locking arm 4 in FIG. 18), there arises a problem that a terminal holding mechanism for locking the terminal 3 may be broken and the terminal 3 may be accidentally come out of the housing 1.
In order to prevent such an excessive deformation of the excessive deformation prevention plate 7, it is proposed to provide a member for pressing the excessive deformation prevention plate 7. However, in this case, since the number of the parts increases, there arises a new problem that the arrangement of the connector becomes complicated, the size thereof becomes large and further the fabrication thereof becomes difficult.